Numerous studies have been made in an effort to improve the processability of the broad class of polymers of conjugated dienes, particularly the solution polymerized polymers. In general, a broader molecular weight distribution is desired in polymers of conjugated dienes including homopolymers of conjugated dienes, copolymers of conjugated dienes, and copolymers of conjugated dienes with monovinyl-substituted aromatic compounds. Polymers of broader molecular weight distribution tend to have more desirable processing characteristics such as better banding on a roll mill, faster and better mixing of compound recipes in an internal mixer, reduced cold flow, as compared to polymers with relatively narrow molecular weight distribution. Improved processability characteristics of solution-polymerized polymers are desired so as to be equivalent to the processability of the emulsion-polymerized polymers. The emulsion-polymerized polymers are more difficult and expensive to make. Improving the properties of the more easily and economically prepared solution-polymerized polymers would improve the competitive position of the latter.